Case 1840 no forward or backward motion. New tandem pump

[tiestarrw]

Hello, I bought a Case 1840 for cheap but with no forward or backward motion. Replaced hydrostatic tandem pump, checked splines, flywheel and shaft. When trying to get it to move, there is no whining from the charge pump, like it is in neutral. It's like the charge pump isn't charging. Checked for leaks and checked to make sure there is oil in the lines. I have the service manual. Anyone have any guesses. I would appreciate the help.